Electromatic retractable defect finder



Oc t. 29, 1963 E.vossEN 1 ELECTROMATIC RETRACTABLE DEFECT FINDER Filed Dec. 30, 1.960

6 INVENTOR EDWARD VOSSEN I MM 5 L? ATT RNEY.

United States Patent York Filed Dec. 30, 1%0, Ser. No. 79,797 4 Claims. (Cl. 66-466) This invention relates to a device for finding defects in fabrics and thereupon stopping the motion of the feeding mechanism and for automatically deactivating said finding device during predetermined intervals t permit passage of special patterns.

Heretofore, hole detectors have been employed in connection with fabric forming machinery, such as knitting machines, to cause the machine to stop upon detection of a defect and thereby prevent wastage. The detector utilized a spring urged feeler member in a piv-otally mounted plunger. The feeler or probe was fonced into the hole and movement of the fabric with respect to the detector caused the plunger to pivot and activate an electric switch which shut off the machine. A device of this type is described in Patent Number 2,691,880, entitled, Rib Hole-Detector for Revolving and Stationary Head Rib Knitting Machines, issued October 19, 19-54, to Edward Vossen and assigned to the same assignee as the instmt application. Under certain circumstances, wherein a special pattern, such as a loosely knitted portion, was desired, the detector would have to be manually blocked to prevent stoppage of the machine as each separated line passed the feeler.

It is therefore the principal object of the present invention to provide automatic retraction of the defect finder during predetermined intervals while permitting normal functioning of the device at other times.

This is accomplished by use of a solenoid and linkage structure which is activated by a cam and switch arrangement. As an illustration, the cam is connected to the revolving frame of a circular knitting machine to activate the switch during appropriate periods and thus permit passage of the desired pattern. The switch activates the solenoid which, in turn, causes the linkage to retract the feeler from the fabric for the predetermined interval. The detailed description and accompanying drawings which follow consider the device in one particular configuration. It is to be understood that this represents but one embodiment chosen for the purposes of explanation and illustration and is not to be construed as defining the limits of the invention.

FIG. 1 is a top view of the instant device;

FIG. 2 is a side view thereof;

FIG. 3 is a vertical section on the line 33- of FIG. 2;

FIG. 4 is a View of the device as mounted on a portion of the knitting machine adjacent the fabric;

FIG. 5 is a schematic of the cam and switch arrangement which activates the retracting solenoid at appropriate periods, FIG. 5 being also a circuit diagram embodying said switch and said solenoid and showing the circuit of the present device.

As shown in FIGS. 1, 2 and 4, the defect finder assembly is mounted on a portion of the knitting machine 12 immediately adjacent the fabric 14. A curved guide plate 16 is mounted at the upper end of the assembly and incorporates a longitudinal slot 18 to accommodate a spring urged feeler or probe 20. -As shown in FIG. 3, the feeler is mounted in a plunger 22 which is normally held in a straight vertical position by springs 44 and balls 46. The springs are mounted on the outer surface of side plates 48 while the balls fit through holes therein to mate with corresponding notches 50 in the plunger. The plunger is positioned adjacent an electric switch 52 and bears against rod 54 to maintain the normally closed switch contacts in a desired open circuit condition.

When the feeler, which rides against the fabric, detects a defect or hole, it springs forward and is caught by the moving fabric. Accordingly, the plunger, which is pivotally mounted about pin 56 on one end of arm 58, is forced to rotate out of position along slot 18. At this time, the contacts of switch 52 spring into a closed circuit condition to activate a remote device which halts the fabric feeding mechanism until the condition is rectified.

A manual re-set lever 60 which is pivotally secured to the assembly may then be utilized to re-position the plunger and permit the mechanism to restart. The lever is connected to a rod 62 which is pivotally secured to the other end of arm 58. When the lever is moved upward, the rod is pulled down and the plunger is brought back into position.

Under certain conditions, it is desirable that the defect finder be disconnected. This may occur, for example, wherein a particular fabric design is knitted which deliberately incorporates spaces or portions having a very loose stitch structure. With the hole detector continuing in operation, the machine would be stopped at each hole and have to be reset each time. In order to overcome this difficulty, the instant novel automatic retraction device is utilized. An electrically energized solenoid 64- controls a plunger 66 which is pivotally connected to a rod 68. A spring 70- also connects the plunger to the main assembly 10. The rod is hooked around a curved extension 72 of feeler 20. Under usual conditions, with the hole detector in operation, movement of the plunger 22 away from switch 52 will not afiicct rod 68 of the retraction device since the rod rides along the curved extension 72 land pivots about plunger 66.

However, when the solenoid is energized, plunger 66 pulls down on rod 68 which then also retracts feeler 26) to prevent the continued detection of holes and stoppage of the machine. Automatic action of the solenoid is obtained by use of cam 74 and switch 76, shown schematically in FIG. 5. The cam is secured to the revolving frame 73 of the knitting machine to coincide with the deactivated needles and the cam is of such shape and dimension that it will close the switch cincuit to operate the retracting solenoid only during the portion of the cycle corresponding to the desired pattern variation. When the cam passes the switch, the circuit opens and the solenoid is deenergized. Plunger 66 is pulled up by spring 70 and the feeler is thereby returned to its operative position projecting through plate 16 and rcenga-ging the fabric for hole detection purposes.

It can thus be seen that the instant invention provides automatic retraction of the defect finder during predetermined intervals to permit passage of desired patterns without continual stoppage of the machine.

The circuit diagram of FIG. 5 discloses the circuit of the present device as applied to a conventional controller, this being the remote means which the present device operates. The circuit is a low voltage circuit which feeds off a conventional transformer. N claim is made herein either to the controller or to the transformer, or even the circuit shown in FIG. 5, said circuit being merely illustrative of the application of the present invention.

While only a single embodiment of the invention has been illustrated, it is apparent that the invention is not limited to the exact form or use indicated and that many variations may be made in the particular design and configuration without departing from the scope of the invention as set forth in the appended claims.

What is claimed is:

l. A device for finding defects in fabric which is moving relative to said device and thereupon stopping said movement, comprising a supporting plate, a curved guide 3 plate mounted on said supporting plate and having a longitudinal slot therethrou gh, a first plunger pivotally mounted on said supporting plate and a spring urged feeler slidably mounted in said first plunger, said feeler having one end normally protruding through said slot to bear against said fabric, an electric switch mounted immediately adjacent said first plunger and having means operated by said first plunger to maintain said switch in a normally deactivated condition, remote means operable by said switch to stop said movement, means for holding said first plunger against said switch under normal conditions and permitting said first plunger to pivot when said feeler finds a defect in said ifabric, said pivoting motion causing said switch to activate and operate said remote means :to stop said movement, and means for automatically retracting said feeler at predetermined intervals of time to prevent said feeler from activating said switch to stop said movement, said automatic retracting means including an electric solenoid having a second plunger slidably mounted therein, a rod pivotally connected at one end to said second plunger and connected at the other end to the other end of said feeler whereby activation of said solenoid causes said second plunger and rod to retract said feeler, and means operable in conjunction with 4 said moving fabric to activate said solenoid at said predetermined intervals.

2. The device of claim 1 wherein said last means includes a cam and a second electric switch.

3. The device of claim 1 wherein said other end of said feeler includes a curved portion and said rod connected thereto includes a hook fitting over said curved portion to permit said plunger to pivot without affecting the operation of said automatic retracting means at times other than during said predetermined intervals, and a spring connected between said supporting plate and said second plunger to maintain said second plunger in a released position at said other times.

4. The device of claim 1 including means for resetting said first plunger, said last means including a lever pivotally connected to said supporting plate and a rod connected at one end to said lever and pivotally connected at the other end to said first plunger.

Vossen Oct. 19, 1954 Antonevich Apr. 26, 1960 

1. A DEVICE FOR FINDING DEFECTS IN FABRIC WHICH IS MOVING RELARTIVE TO SAID DEVICE AND THERUPON STOPPING SAID MOVEMENT, COMPRISING A SUPPORTING PLATE, A CURVED GUIDE PLATE MOUNTED ON SAID SUPPORTING PLATE AND HAVING A LONGITUDINAL SLOT THERETHROUGH, A FIRST PLUNGER PIVOTALLY MOUNTED ON SAID SUPPORTING PLATE AND A SPRING URGED FEELER SLIDABLY MOUNTED IN SAID FIRST PLUNGER, SAID FEELER HAVING ONE END NORMALLY PROTRUDING THROUGH SAID SLOT TO BEAR AGAINST SAID FABRIC, AN ELECTRIC SWITCH MOUNTED IMMEDIATELY ADJACENT SAID FIRST PLUNGER AND HAVING MEANS OPERATED BY SAID FIRST PLUNGER TO MAINTAIN SWITCH IN A NORMALLY DEACTIVATED CONDITION, REMOTE MEANS OPERABLE BY SAID SWITCH TO STOP SAID MOVEMENT, MEANS FOR HOLDING SAID FIRST PLUNGER AGAINST SAID SWITCH UNDER NORMAL CONDITIONS AND PERMITTING SAID FIRST PLUNGER TO PIVOT WHEN SAID FEELER FINDS A DEFLECT IN SAID FABRIC, SAID PIVOTING MOTION CAUSING SAID SWITCH TO ACTIVATE AND OPERATE SAID REMOTE MEANS TO STOP SAID MOVEMENT, AND MEANS FOR AUTOMATICALLY RETRACTING SAID FEELER AT PREDETERMINED INTERVALS OF TIME TO PREVENT SAID FEELER FROM ACTIVATING SAID SWITCH TO STOP SAID MOVEMENT, SAID AUTOMATIC RETRACTING MEANS INCLUDING AN ELECTRIC SOLENOID HAVING A SECOND PLUNGER SLIDABLY MOUNTED THEREIN, A ROD PIVOTALLY CONNECTED AT ONE END TO SAID SECOND PLUNGER AND CONNECTED AT THE OTHER END TO THE OTHER END OF SAID FEELER WHEREBY ACTIVATION OF SAID SOLENOID CAUSES SAID SECOND PLUNGER AND ROD TO RETRACT SAID FEELER, AND MEANS OPERABLE IN CONJUCTION WITH SAID MOVING FABRIC TO ACTIVATE SAID SOLENOID AT SAID PREDETERMINED INTERVALS. 